The Asian cave Diving Club finally reached the bottom of Sra Keow cave in Thailand. Sra Keow Cave is located near Krabi, Thailand. It's the third of a serie of expeditions organized by the Asian Cave Diving Club in order to explore what is for now on the deepest flooded cave in South-East Asia.

Thanks to an impressive logistics and several set-up dives, the team reached a maximum depth of 240m/784ffw (measured with a calibrated Liquivision F1 depth gauge) during a 10-hour dive conducted on the 18th of february 2007. During this dive, the deep divers safely explored and surveyed the deepest part of the cave. They used open circuit scuba and Closed-Circuit Rebreather, to a dive that might be the deepest mixed-team dive ever.Decompression was calculated with V-Planner software and was partly done in a very comfortable habitat under the direct supervision of a medical team.

Special thanks to Mike Gadd who participated in the beginning of the expedition and was a key member of the team.

Logistics by One Stop Dive Shop, Deep Blue Divers, Ocean Zone Divers, Igor's Dive Center and Protec Divers. A very special thanks to Dave and Glyn from One Stop Shop in Krabi, Dive Supply, Sea Fun Divers, Liquivision and their great F1 depth gauges.Weezle, DUI, Ralph Tech and O'Three kept the divers warm and SSP, Aunoc and Green Force provided them with efficient lights at depth.Thanks to ISC, DIRrebreather and Golem Gear for the rebreathers and accessories.

For more information:http://asiancavediving.blogspot.comhttp://www.deepcult.comhttp://www.cedricverdier.com

note:This dive required a lot of logistics and effort from a large group of people. Before the dive an agreement was made that the deepest depth reached, by whomever, would be teams result as such. The goal was not to reach a record depth, but to find the origin or bottom of the cave.

Sra Keow cave system is different than the other Thai caves; it has no stalactite/stalagmite formations below 40 meters, but signs of water erosion.If you hover motionless near the entrance, you would notice a very gentle flow, streaming out of the cave Talking to geologist, woke our curiosity; oh, these caves can go well beyond a depth of 300metres of depth. An 80m white rock wall towers on the edges of a small pond in the middle of the jungle. The pond itself isnt larger than an average backyard and is the favorite drinking spot for passing elephants. The local Thais know its the entrance of a large cave system, connecting with another pond at great depth.

Mauricio and Eefje are struggling to read the wetnote Cedric send up. My heart is pounding in my throat if Cedric used any of his bail out gas Ill have to climb out of my 80 kg rig and start blending again.

240M BAD VIZ, ROPE ENTANGLED, TELL BEN TO USE THE 186M LINE

Not sure what to make out of it and a little worried I learn that the bottom gasses are untouched. Cedric will make it to the habitat solely using his Megalodon ccr quiet an achievement An elephant would perform a more elegant giant stride entry and I quickly disappear in the muddy pool. At 12m, the cave starts where the visibility is reduced to 1m. Rows of deco tanks pass me by as I drop fast. In a glimpse I see Cedric through the silt around 30m. After just 4 minutes I pass the 60 meter mark and a bit later I pick up my last intermediate Trimix that Cedric has left for me. The visibility now gets better, the angle steeper and the finning is less heavy to keep up with the diagonal descent. The visibility now increases and I still try go grasp the dimensions of the cave. The stalactites have disappeared and running water has performed a genuine piece of art in the limestone. Even with my Green force HID light, the far wall remains a black hole.

The descent is now almost vertical and the sound of my heavy breathing is slowly being replaced by the pounding of my heart in my ears. The magical 150m tie off .

I tried to reach this tie off three days earlier, but failed to do so because of a slow descent and the labor of staging tanks at 108m. Cedric had warned me that the big pinnacle at 150m was the last decent tie-off and the rest was nothing more than small rock flakes with the end of the line at 186m. We had been brainstorming for the last three days how to put a main drop line from 150m without losing an expensive reel, but putting a weight on it regardless. Finally we decided that Cedric would tie off a weighted spool at the 150m mark, ignore the old line and descend with the spool to his maximum depth, leave it locked with bungee and a cyalume in case I managed to get deeper.

The 150m tie off is smaller than I imagine and I find the spool, a weighted line going down and about 20m of neatly knotted line, all fixed to the mainline. Not looking good, so I follow the old line that follows the ceiling for a few meters before plumbing along the opposite wall into the deep. I follow it to 186 meter where it stops in a basic tie of with a simple loose knot . Not too much, but its all I have. I take my OMS reel, tie off on the old line and look up to whoever is watching that it will hold for just a few minutes.I unlock the reel, drain my BCD and start dropping and darkness closes in. The walls have disappeared now and the only visual reference is a slowly spinning reel in front of my eyes and my bright yellow F1 depth gauge. My Suunto Vytec has gone to sleep since 150m What the hell am I doing here?Around 190m High Pressure Nervous Syndrome kicks in. 85% of Helium and a fast descend make my hands shake and I feel tremors along my spine. Im not carrying a pressure gauge out of risk for implosion; the manifold valve on my twin tank is closed and as soon as breathing becomes difficult, I would open the manifold valve, and start my ascend. 210m , the shaking in my hands has become worse and I doubt that I will be able to open the manifold valve on my back. I decide to open it now, breathe my 3rd bail-out tank empty and then ascend. The noise is overwhelming when both tanks equalize.Suddenly I get hit by something one of the walls wall has sneaked up on me and I bounce off. Finning to regain my balance, a few seconds later I bounce of a wall coming from the left hand side. Is the cave this narrow or is my orientation completely gone?I can only see one ochre colored wall with clear signs of water erosion and the rest is black. I look up and I see a large cloud of dust following me.My gauge reads 230m and 24 minutes runtime. All seems to be going well The next minute everything goes very fast. I hit a muddy slope and nearly tip over. A few finkicks get me off the slope and another straight drop follows.The feeling of falling into a giant duvet blanket shoots through my head The bottom is composed out of fine yellow silt and very gently I sink in it up to my knees, getting me to a full stop . My gauge reads 240m. I look around, the bottom appears flat, maybe a slight inclination but I fail to see another drop. I can see three walls closing the space, but the far end remains black. The silt starts to come up to my chest and instinct tells me its time to go back. I look at my expensive OMS reel that has been my faithful buddy for years. With hands shaking like this, theres no way I can reel it back in. I lock it up, start inflating my BCD and slowly I come free out of the mud leaving a trail similar to that of an junior space shuttle.

Slow ascend, slow breathing, slow ascend, slow breathing I keep telling myself . The minutes look like hours while being hypnotized by the numbers on my gauge and line gliding though my hands on the way upwards. My first stop is at 186m, exactly at my tie off. I look at it and still cant believe I trusted such a little piece of string with a dodgy knot. I recover the spool Cedric has left as a souvenir at 150m.A bleep , a clear blue screen and my Vytec computer jumps back to life. I reach the first series of stage tanks at 108 meters. They have been here for 3 days and are covered in a slimy brown layer of dust The mouthpiece has a few shrimps on it and after a quick swipe I put the delicacy in my mouth The rest of the ascent goes smooth until I hit the T-junction at 80m. I first see the red arrow, and then I look at the yellow one. Because of my bright HID, the red colors are still dancing on my cornea making the yellow appear red. Confusing I arrive at 66 and see no tanks. My heart stops . Did I take the wrong turn at the T-junction? Im sure I followed the yellow arrow and not the red one The red arrow leads too another pool without deco gas or habitat I ascend another meter. The visibility is about 1 meter here.. at 64 meter I bump with my head into the deco tanks. The silt from the last three days has covered the tanks completely, making a perfect cave camouflage. Im back on the happy track, I clean the second stage clear from half a pound of mud and shrimps and start breathing my decogas.

I switch from my 14/70 mix to my 21/50 mix within 30 seconds my head starts spinning. The passage in the cave is pretty narrow here and while struggling with my tanks, Ive reduced the viz to less than 10cm. The vertigo gets worse and Im convinced that I suffering inner ear decompression sickness due to the nitrogen load hitting my inner ear . . If this gets worse I risk drowning in my own vomit.Not today I switch back to my 14/70 and miraculously the dizziness oozes off now what? I cant keep breathing this mix since itll jeopardize my schedule, get me bent and it will soon be depleted anyways I opt for a cocktail and start alternating regs every 5 breaths this seems to do the job, after 10 minutes I manage to breathe the 21/50 with more or less stabilized vertigo .

I follow my 250m plan out of conservatism and simply because I dont carry a plan for 240m. The surface crew assumes the deepest expected plan for 270m. I was shallower and earlier, so I dont expect Mauricio, my deep support diver until 50m.

This puts me a bit into trouble as there is no one to take my stages off me and Im forced to clip them on. 5 tanks on my back, two stages sidemounted left, two stages sidemounted right. 2 stages clipped on a d-ring on my twins right, while pushing the stage Im breathing along the line its all a bit over the top and I urgently need to organize my gasses and make inventory.

At 50m my savior shows up, whacks me a slate in my hands with lots of questions and I am 6 tanks lighter. In the haste we lose a tank which I will later find back stuck against the ceiling The freshwater shrimps apparently have put Belgian diver on the menu for this evening and find little gaps between gloves and hood to pick flesh.I reach 39m and see the next decostation with 3 tanks. A few hours later, the 21 meter stop appears and Im again in overload; pushing 4 tanks ahead of me while dragging 9 tanks on every d-ring on my harness I hope Laurent shows up quickly.

Laurent needs two runs to get all the tanks to the surface and after 5 hours I finally reach my 12 meter stop. Shrimps everywhere. The shrimp cook on duty points out that the divers lips are the best and in my effort to wipe them away I lose my dive plan . Im all sorted now. My back-up plan is unreadable since I punched holes through the laminate and it has become flooded. Im cold, dizzy, hungry and I cant see a thing. On the surface, kids started playing in the pond and every time one jumps in I get a cloud of silt on top of me.

I finally finish my last stop, time to get into the habitat. I struggle out of my gear and surface next to a smiling Cedric who has been in here for the last three hours. I wedge myself on my primitive seat while Cedric hand feeds me hot soup brought by the surface support. I feel like shit. I have difficulty talking, my knees hurt, my head is spinning and my stomach is in a knot .

Bottom at 240 huh? I ask cedric .He looks at me with big eyes and says you saw the bottom?

Im confused Cedric sees the confusion on my face and explains; No bottom; I tied the spool on the 150m rock, started descending and suddenly the entire line inclusive rock, came falling past me. I caught the main line before it disappeared, ascended, made a new tie off and wrapped all the loose line into a knot.Iwent to 186, but spent longer than my allowed bottom time, thats why I took the 240m plan

I cant believe it if he would have lost the main line, that would have been a certain death for him, no way to find the exit passage again. In order not to get me entangled he spent longer than his allowed bottom time collecting loose line. He stays almost half an hour longer in the habitat to make up for it We finish our soup and squeeze potato puree out of plastic bags while breathing 80% from surface supplied hoses which taste of polyvinyl nice one shrimps have also gathered on our submerged laps in the habitat, taking a serious interest in the pee-valves on my OThree dry-suit in the meanwhile, the cyalume lights started dripping their luminous fluid into the habitat pool, giving a phosphorus plankton-like show. They obviously didnt like the pressure and even being liquid filled, the tiny air bubble inside caused them to burst. In no time, most of our pouches and gear are glowing in the dark. Arent these things toxic?

I read magazines, finish the mashed potatoes and 3 hours later it is finally my turn. Luba, our dive doc shows up to escort me out of the habitat on a full face mask. As soon as we ascend my knees start to hurt. I wait for a few minutes until the pain fades, but as soon as I ascend another meter, the pain comes back. In the end it takes me about 15 minutes to get to the surface and I float another half an hour around to let the pain go away before returning to gravity the divesite is a mess , tanks everywhere, hoses left and right, suits , fins, food containers etc Then a lightning and two seconds later it is pouring down. I must have upset the gods of the cave This is supposed to be dry season.I arrive back in Phuket at 1 am with a truck full of mud-covered dive gear, convinced that I will never dive in such a horrible cave again or will I?I used z-planner and open circuit for this dive with 60% safety factor. I believe the introduction of nitrogen in the shallower areas <70m was still too aggressive could have been reduced, keeping the N2-He balance constant, whilst only increasing the PPO2